DouKaku?

(use util.stream)
(use gauche.collection)

(define (integers-starting-from n)
  (stream-cons n (integers-starting-from (+ n 1))))

(define (sieve stream)
  (define (divisible? x y) (= (remainder x y) 0))
  (stream-cons
   (stream-car stream)
   (sieve (stream-filter
           (lambda (x) (not (divisible? x (stream-car stream))))
           (stream-cdr stream)))))

(define primes (sieve (integers-starting-from 2)))

(define (number->digit-stream n)
  (stream-map
   (lambda (c) (- (char->integer c) (char->integer #\0)))
   (string->stream (number->string n))))

(define (goedel n)
  (apply * (stream->list
            (stream-map (lambda (pk nk) (expt pk nk))
                        primes (number->digit-stream n)))))